States have increasingly started to terminate and renegotiate their bilateral investment treaties (BITs). Dominant explanations have however overlooked the underlying bargaining dynamic of investment treaty negotiations. This paper argues that while states initially in a weaker negotiating position have the strongest incentives to change their existing BITs, their ability to do so is constrained by their bargaining power. Such states become more likely to demand renegotiation or exit dissatisfying BITs if they have experienced sufficient changes in their bargaining power in relation to the treaty partner. This paper identifies observable implications of the weaker states’ incentives and bargaining power constraints for adjusting their bilateral investment treaty commitments. Leveraging a panel dataset on 2,623 BITs ranging from 1962 to 2019, interaction effects between bargaining power and incentives stemming from rationalist and bounded rationality assumptions about states’ decision-making are analyzed in relation to the occurrence of renegotiations and terminations. The paper finds that change in bargaining power in relation to the treaty partner is an important factor underlying the weaker states’ ability to terminate or renegotiate BITs, contributing to the study of investment regime reform and exit from international institutions.

越来越多的国家开始终止和重新谈判双边投资条约（BITs）。然而，占主导地位的解释忽略了投资条约谈判的潜在讨价还价动态。本文认为，虽然最初处于较弱谈判地位的国家有最强烈的动机来改变其现有的双边投资条约，但它们这样做的能力受到其议价能力的限制。如果这些国家在与条约伙伴有关的议价能力方面经历了足够的变化，则更有可能要求重新谈判或退出不满意的双边投资条约。本文确定了弱国的激励措施和议价能力限制对调整其双边投资条约承诺的可观察到的影响。利用从 1962 年到 2019 年的 2,623 个 BIT 的面板数据集，议价能力与源自理性主义和有限理性假设的国家决策的激励之间的相互作用效应与重新谈判和终止的发生相关进行了分析。论文发现，与条约伙伴相关的议价能力变化是弱国终止或重新谈判双边投资条约能力的重要因素，有助于研究投资体制改革和退出国际机构。